Problem: Solve for $p$ : $-23 = -1 + p$
Answer: Add $1$ to both sides: $ \begin{eqnarray} \\ \hphantom{-23 {+ 1}} &\hphantom{=}& \hphantom{p} \\ -23 &=& -1 + p \\ \\ {+1} && {+1} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ -23 {+ 1} &=& p \\ \end{eqnarray} $ Simplify. $ p = -22$